What are the causes of stones in the bladder and prevention

Stones in the bladder

THE DOCTOR SAYS
By DR MILTON LUM



BLADDER stones (calculi) are common, particularly in tropical climates. Bladder calculi are less common than kidney calculi. The former are usually a consequence of urinary tract conditions, in which there is stasis of urine, e.g. urinary tract infections, especially recurrent ones, bladder diverticulum, enlarged prostate and conditions of the nervous system, although they can also occur in healthy people.

The presence of calculi in the kidneys and ureters does not necessarily mean that the risk of bladder calculi is increased.

Most bladder calculi occur in adult males. However they can also occur in children. The materials that comprise bladder calculi in adults include uric acid, calcium and ammonium compounds. It is not uncommon to find that the core of a calculus is of one particular chemical surrounded by layers of different chemicals around it.
The materials that comprise bladder calculi in adults include uric acid, calcium and ammonium compounds.

The factors associated with bladder calculi in children include bladder diverticulum, infant feeding with breast milk and polished rice, high intake of animal proteins, and spinal cord conditions.

Most bladder calculi arise from the bladder itself. However, some calculi are initially formed in the kidney and are then passed into the bladder when additional deposits lead to an increase in the size of the calculi. The renal calculi which are tiny enough to traverse the ureters to reach the bladder are also tiny enough to be passed out when bladder function is normal and there is no obstruction in the channel that leads from the bladder to the exterior (urethra).

Bladder calculi can be single or multiple and are of various sizes. Although most bladder calculi are mobile, there are some which are adherent to the bladder.

Clinical features

Some people with bladder calculi have no symptoms.

For those with symptoms, these arise from the calculus irritating the bladder or obstructing the flow of urine from the bladder.

The common symptoms include lower abdominal pain or pressure, pain on passing urine (dysuria), frequent passing of urine (frequency), passing urine at night (nocturia), interruption of urine flow (hesitancy) and retention of urine.

Other common symptoms include blood in the urine (haematuria), urge to pass urine (urgency), sudden stopping when passing urine associated with pain at the tip of the penis, scrotum or back, and inability to pass urine except when in certain positions. There may also be incontinence and fever.

There may be a history of previous pelvic surgery.

The common findings on physical examination include lower abdominal tenderness above the pubic bone and a palpable bladder if there is urinary retention. Rectal examination may reveal an enlarged prostate. There will be signs of neurological dysfunction if there is a disorder of the nervous system.

Children with bladder calculi may have persistent erection of the penis, which is unrelated to any stimulation and/or occasional involuntary passage of urine at night (nocturnal enuresis), the latter resulting in bedwetting.

The complications of untreated or inadequately treated bladder calculi include obstruction of the upper urinary tract, urinary tract infection, incontinence of urine, urinary retention, recurrence of the calculi and permanent damage to the bladder and/or kidneys.

Management

Laboratory and imaging tests may be done. They will provide information about the presence of calculi, their nature, and associated or causative conditions.

An abdominal or pelvic x-ray will reveal radio-opaque calculi. However, uric acid calculi are radiolucent and may not be seen on the x-rays if they are not coated with calcium. Bladder calculi are also commonly diagnosed by computerised x-ray tomography (CT scan) and ultrasound.

Microscopic examination of the urine may reveal the presence of an infection, blood or crystals. Culture of a mid-stream specimen of the urine may reveal a urinary tract infection.

Many people get rid of the bladder calculi by themselves, i.e. they pass out the calculi when urinating. This often happens with small calculi.

Cystoscopy is a procedure in which a telescope-like instrument is inserted through the urethra under anaesthesia to visualise the inside of the bladder and its contents, if any. It is a common method used to diagnose bladder calculi.

After the calculus or calculi has been visualised, it is broken up into fragments with an energy source, which include mechanical, ultrasonic and laser. The fragments are then removed through the cystoscope.

The miniaturisation of these instruments has made it possible for the use of the treatment modalities in selected children, whose urethral diameter is usually smaller than that of adults. Complications are few and usually minor in nature. They include urinary tract infection, fever, perforation of the bladder, and bleeding.

In general, the majority of bladder calculi are surgically removed through the cystoscope. However, there are situations in which the calculi are too large or hard or when access to the bladder is limited by a narrow urethra, e.g. in children. In such situations, the percutaneous or open suprapubic surgical approach is used.

The percutaneous approach involves approaching the bladder through the skin above the pubic bone. This is the main approach in children. It permits the use of larger diameter and shorter endoscopic equipment to rapidly break up the calculi, which are then removed. It is not uncommon that the urethral and percutaneous approaches are used together to stabilise the calculi; break it up followed by removal of the fragmented debris.

Open suprapubic cystotomy is an operation in which the bladder is surgically opened and the calculi removed. This method is used when the calculi are large and/or hard and when open prostatectomy and/or removal of bladder diverticula is done.

The advantages of this method are the easy and rapid removal of several calculi at a time, the removal of large calculi, and the removal of calculi that are stuck to the bladder surface. Its disadvantages include longer hospital stay, post-operative pain and longer bladder catheterisation times.

Other procedures may be done at the same time as removal of the bladder calculi, e.g. removal of an enlarged prostate.

The conditions which are contraindications to the surgical removal of bladder calculi are few. These include pregnancy and poor general health of the patient.

Medicines are sometimes used in the management of bladder calculi. The only potentially effective medicine is the alkalinisation of urine to dissolve uric acid stones. However, excessive alkalinisation may result in phosphate deposits on the uric acid calculi surface, thereby rendering ineffective any further medical treatment.

Prevention

Bladder calculi can be prevented by prompt and effective treatment of urinary tract infections and treatment of conditions affecting the lower urinary tract. Drinking sufficient fluids daily would also help in preventing bladder calculi formation and facilitating the expulsion of the calculi from the body.

Dr Milton Lum is a member of the board of Medical Defence Malaysia. This article is not intended to replace, dictate or define evaluation by a qualified doctor. The views expressed do not represent that of any organisation the writer is associated with.

Credits to and source taken from: http://thestar.com.my